Modular Flexible Current Sensing Coil for Scalable Precision Measurement

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional current sensing devices, such as current shunts, current transformers, Hall Effect sensors, and traditional Rogowski coils, face limitations like size constraints, heating issues, current saturation, labor-intensive assembly, and non-modularity, which hinder accurate and scalable current measurement in industrial applications.

Innovation Solution

A modular current sensing system utilizing a flexible circuit with conductive windings on both sides of cells, a stress reduction feature, and a sealing element, stacked in a configuration to enhance magnetic flux additivity, and electrically coupled to a rigid support structure for adjustable current detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional Rogowski coils with multiple bobbins and series-wound turns are used, then current measurement capability is achieved, but assembly becomes very labor intensive and costly

Engineering Contradiction:
Improvecurrent measurement capabilityVSAvoidassembly labor intensity
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The Rogowski coil is segmented into multiple modular detecting units, each containing a flexible circuit with conductive windings. These units can be independently manufactured and then assembled by stacking, replacing the traditional labor-intensive process of winding multiple bobbins in series. The segmentation enables standardized production of individual units that are easily combined to achieve the desired measurement range.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent uses flexible circuits with printed conductive windings instead of traditional rigid bobbins with hand-wound wires. The flexible circuit substrate allows for automated printing processes and simplifies the manufacturing of the coil structure, dramatically reducing assembly labor while maintaining the necessary electrical characteristics for current measurement.

Inventive Principle:
Principle #30Flexible shells and thin films

2Measurement precision

If conventional current sensing devices are used, then current measurement is possible, but the systems are not modular and cannot easily scale to sense multiple current levels

Engineering Contradiction:
Improvecurrent measurementVSAvoidscalability to multiple current levels
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The system is designed with modular detecting units that can be dynamically configured by stacking different numbers of units together. This allows the system to adapt to different current measurement requirements by simply adding or removing units, providing scalability across multiple current levels without redesigning the entire sensor system.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

Each detecting unit is designed as a universal module that can function independently or be combined with other identical units. The standardized interface and additive magnetic flux design allow any number of units to be stacked to measure different current levels, making the system universally applicable across a range of measurement requirements.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Measurement precision

If flexible circuit is folded into stacked configuration to enhance magnetic flux additivity, then sensitivity is improved, but stress on the flexible circuit increases

Engineering Contradiction:
ImprovesensitivityVSAvoidflexible circuit stress
Core Design Contradiction:
Measurement precisionVSStrength

Solution Approach 1:

Stress reduction features are incorporated into the flexible circuit design before the stacking process. These features, such as relief cuts or flexible zones, are pre-positioned to accommodate the bending stresses that will occur during folding, preventing damage to the conductive windings while enabling the stacked configuration needed for enhanced sensitivity.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The system achieves improved power density, simplified manufacturing, and enhanced sensitivity, allowing for precise current measurement across varying levels, addressing the limitations of existing technologies while being modular and scalable.

Implementation Method 1

magnetic flux generated by the conductive windings are mutually additive

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP2960661B1A modular current sensing system and a method of making a modular current sensing system
Publication Date: 2024.01.31 ABB SPA
  • EP2960661B1 patent drawingFigure 1
  • EP2960661B1 patent drawingFigure 2~3
  • EP2960661B1 patent drawingFigure 4~5

AI summary

A detecting unit (102) is presented. The detecting unit (102) includes a flexible circuit (202) having a first side (200) and a second side opposite the first side. The flexible circuit (202) includes a plurality of cells (204) defined therein, each of the plurality of cells (204) having a first side and a second side respectively corresponding to the first side (200) and the second side of the flexible circuit (202). Moreover, the flexible circuit (202) includes a plurality of conductive windings (216) disposed on at least one of the first and second sides of the plurality of cells. Further, the flexible circuit (202) includes a stress reduction feature (220) between each of the plurality of cells (204). Also, the detecting unit (102) includes a sealing element configured to secure the flexible circuit (202) in a stacked configuration. A sensing system and a method of making a detecting unit (102) are also presented.